Bio-film was successfully formed by making use of the natural purifying microbe in the sea for the industrial recirculation aquaculture systems. The nitrification impact factors, including water temperatures, influent ammonia-nitrogen concentrations and hydraulic retention time (HRT) were also explored . The results showed that at the same influent ammonia-nitrogen concentration and HRT, the ammonia-nitrogen concentrations changed significantly at different water temperatures (P<0.05). When the water temperature was 28℃, after purified by bio-film for 120 hours, the influent ammonia-nitrogen concentration dropped to the lowest concentration. The ammonia-nitrogen removal rate and the specific ammonia removal rate were gradually increased as the influent ammonia-nitrogen concentration and HRT increased. However, at the same ammonia-nitrogen concentration, the specific ammonia-nitrogen removal rate decreased as HRT was prolonged.